Lid for a pan, plate, bowl or the like

ABSTRACT

A vacuum seal lid for turning existing containers including plate, bowl, pan and even cutting board into a vacuum storage container comprises a top plate having an opening, a sidewall, sealing means for preserving vacuum, and a knob adapted to be at a first position in which it is above the opening to facilitate evacuation and handling, a second position in which it is at least partly below the opening to facilitate stacking and storage and a third position between the first and second positions in which the vacuum is released. The top plate may further comprise a first plate in which the opening is located and a second plate having an elastic membrane and a smooth lower surface constituting part of the sealing means for sealing containers smaller than the lid. The sealing means also comprises a sealing membrane located below the bottom surface or on the outer surface of the sidewall for sealing containers larger than the lid. To improve the seal, the sealing membrane is separable or apart from the bottom or outer surface of the sidewall. To improve the seal further, at least part of the sealing membrane is sloped at an angle relative to a horizontal plane. The knob has a knob head, a valve opening, and a valve sealer adapted to clean the valve opening by moving the knob head to improve the reliability of the lid.

FIELD OF THE INVENTION

This invention relates to a lid or cover for a container such as a pan,plate or bowl, particularly to a lid that forms an airtight seal, andmore particularly to a lid that forms a vacuum seal to the container.

BACKGROUND OF THE INVENTION

Lids or covers have been ubiquitously used for pans and plates, andtypically adopt dome shape and have a knob or handle for easy handling.Since the seal between the lid and the pan or plate is typically notairtight, such lids are not well suited for storage. In addition, theprotruded handle prevents the containers covered by the lids fromstacking over each other to save space.

Numerous vacuum seal lids, as known in FoodSave® and Seal-A-Meal vacuumcontainers or taught in exemplar U.S. Pat. Nos. 5,969,632, 6,619,493 and7,131,550, were invented for specially made containers. For unknownreasons, however, few airtight lids were invented to fit the existingcontainers such as pans and plates. Among such airtight lids, Piccionitaught in US publication number 2009/0173735 a bell shaped glass lidfitted with a U-shaped soft structure 4 to seal to dish, Hsieh taught inUS publication number 2009/0101535 a dome shaped lid having a top valvefor allowing a pump to evacuate air and a bottom gasket 30 for sealingto the container, and the applicant taught in U.S. Pat. No. 7,594,586and US publication numbers 2006/0032852 and 2010/0018169 a lid having adisc shape that can vacuum seal nearly all containers.

Picconi's lid is susceptible to air leakage since the plastic structure4 may be too rigid to conform to the topography of the dish to form acomplete seal. Hsieh's lid is similar to that commercialized by RoyalSovereign International Inc and is also susceptible to leakage,especially after the lid was washed in dishwasher or when the vacuumlevel is low. The leakage was possibly caused by insufficientconformation of the gasket 30 to the small indents or protrusions on thesurface of most dish plates or by the food residue or dust caughtbetween the circular seal 293 and the slot surface of the groove 61 andvent hole 63 of the top valve which is difficult to reach by normalwashing. The applicant's lid, commercialized under Keepeez® brand,conforms well to the topography of the container to form a completeseal, but still has some drawbacks such as not working well with platesor with containers larger than the lid.

The present invention is to provide a new lid to simplify the process ofpreparing and storing products such as food and solve the problems withthe prior lids described above.

SUMMARY OF THE INVENTION

A vacuum seal lid is provided to turn existing containers includingplate, bowl, pan and even cutting board into a vacuum storage container.The lid comprises a top plate having an opening, a sidewall, sealingmeans for preserving vacuum, and a knob connected to the top plate andadapted to be at a first position in which it is above the opening tofacilitate evacuation and handling, a second position in which it is atleast partly below the opening to facilitate stacking and storage and athird position between the first and second positions in which thevacuum is released. In a first embodiment of the invention, the topplate comprises one rigid plate to which the knob is hosted. In a secondembodiment of the invention the top plate comprises a first plate inwhich the opening is located and a second plate having an elasticmembrane to which the knob is attached and a smooth lower surfaceconstituting part of the sealing means for sealing containers smallerthan the lid. The elastic membrane of the second embodiment is affixedto the sidewall by a membrane lock having a first and second ridgesseparated only by the second plate or elastic membrane and received bytwo channels on the side wall and first plate to prevent potentialdetachment of the membrane.

The sealing means further comprises an elastic sealer having an elasticsealing membrane located at least party below the bottom surface or onthe outer surface of the sidewall for sealing containers larger than thelid. To improve the seal, the sealing membrane is separable or apartfrom the bottom or outer surface of the sidewall. To improve the sealfurther, at least part of the sealing membrane is sloped at an anglerelative to a horizontal plane. In one embodiment of the invention, theelastic sealer is attached to the bottom of the sidewall and the sealingmembrane has one end connected to the bottom of the elastic sealer andthe other end movable relative to the bottom of the elastic sealer. Inanother embodiment of the invention, the sealing membrane comprises apart of the second plate or elastic membrane located below the bottomsurface or on the outer surface of the sidewall. In yet anotherembodiment of the invention, the sidewall comprises an inner sidewalland an outer sidewall and the sealing membrane is sloped at an anglepreferably larger than 30 degrees and most preferably larger than 50degrees between the inner and out sidewalls.

The knob, in one embodiment of the invention, comprises a knob head, abody fitted frictionally to the opening, a valve chamber having atubular opening for frictionally receiving a tube of an evacuationdevice and a valve opening on its bottom plate, and a valve sealer forcovering the valve opening and having a stem body and a head extendedabove the tubular opening. In another embodiment of the invention, theknob comprises a knob head, a valve opening, and a valve sealerfrictionally fitted into the valve opening and adapted to clean thevalve opening by moving the knob head to improve the reliability of thelid. A loss or partial loss of the frictional fit results in an airpassage for the valve opening. The knob has a motion sealing distance,which is the maximum distance the valve sealer may move without causingany air passage, between about 0.5 mm to 15 mm, preferably between 1 mmand 7 mm, to prevent leakage.

The present invention further provides a method of use comprisingplacing the lid on a container, pressing or pushing the knob head downto form a first air passage to evacuate the container, thus vacuumsealing the lid to the container, and pulling the knob head up to form asecond air passage to release the vacuum, thus lifting the lid away fromthe container.

DESCRIPTION OF THE DRAWING

The accompanying drawing illustrates diagrammatically non-limitativeembodiment of the invention, as follows:

FIG. 1 is a section view of a lid or cover on a dish showing a knob in aprotruded position;

FIG. 1 a is a section view of the lid of FIG. 1 showing the knob in arecessed position;

FIG. 2 is a section view of a first modified version for the lid of FIG.1 showing the knob in a protruded position;

FIG. 2 a is a section view of the lid of FIG. 2 showing the knob in arecessed position;

FIG. 2 b is a section view of an evacuation device for connecting thelid to a vacuum pump (not shown);

FIG. 3 is a section view of a second modified version for lid of FIG. 1when not in use or prior to being applied to a plate larger than thelid;

FIG. 3 a is a section view of the lid along line A-A of FIG. 3;

FIG. 3 b is a section view of the lid along line B-B of FIG. 3;

FIG. 3 c is a section view of the lid along line C-C of FIG. 3;

FIG. 3 d is a section view of an improved membrane lock for the lid ofFIG. 3.

FIG. 3 e is a section view of the lid along line E-E of FIG. 3 d.

FIG. 4 is a section view of the lid of FIG. 3, where the knob is pressedto evacuate the container;

FIG. 4 a is a section view of the lid of FIG. 3, showing the position ofknob after vacuum is formed;

FIG. 4 b is a section view of the lid of FIG. 3, where the knob ispulled up to release the vacuum;

FIG. 4 c is a section view of the lid of FIG. 3 after being sealed to abowl smaller than the lid;

FIG. 4 d is a section view of the lid of FIG. 3 with the evacuationdevice of FIG. 2 b, where the container has been evacuated by a vacuumpump (not shown) connected to the device;

FIG. 5 is a section view of a third modified version for the lid of FIG.1 when not in use or prior to being applied to a plate larger than thelid;

FIG. 5 a is a section view of the lid of FIG. 5, where the knob ispressed to evacuate the container;

FIG. 5 b is a section view of an evacuation device for connection to thelid of FIG. 5;

FIG. 5 c is a section view of a first modified version for the elasticsealer 10 of FIG. 5;

FIG. 5 d is a section view of a second modified version for the elasticsealer 10 of FIG. 5;

FIG. 6 is a section view of a fourth modified version for the lid ofFIG. 1 vacuum-sealed to a plate;

FIG. 7 is a section view of a fifth modified version for the lid of FIG.1 when not in use or prior to being applied to a bowl larger than thelid;

FIG. 7 a is a section view of the lid along line A-A of FIG. 7;

FIG. 7 b is a section view of the lid along line B-B of FIG. 7;

FIG. 7 c is a section view of the lid of FIG. 7, showing the lidvacuum-sealed to the bowl;

FIG. 7 d is a section view of an improved version of the lid of FIG. 7;

FIG. 8 is a section view of a sixth modified version for the lid of FIG.1;

FIG. 8 a is a section view of the lid of FIG. 8 vacuum-sealed to abottle;

FIG. 8 b is a section view of an alternative elastic sealer for the lidsof FIGS. 7 and 8;

FIG. 9 is a section view of a seventh modified version for the lid ofFIG. 1;

FIG. 9 a is a section view of the lid of FIG. 9 when the knob is pressedto evacuate a container;

FIG. 9 b is a section view of the lid of FIG. 9 when device of FIG. 2 bis inserted into the knob.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIGS. 1 and 1 a show a round lid or cover 1 for sealing food 20 in adish plate 21 having a rim 24 and interior surface 23. Lid 1 comprises atop plate 30, an elastic sealer 10 to seal to interior surface 23 toform a closed chamber 22 between the top plate and dish, a sidewall 29,and a knob 50 for facilitating the removal of the lid. Sidewall 29comprises a body 28, an outwardly protruded upper end 6, and a lower endhaving a bottom surface 15, a lower outwardly protruded ridge 14 and anupper outwardly protruded ridge 27 to receive elastic sealer 10. Upperend 6 is received in a skirt 4 of top plate 30, and the skirt is bendedat its lower end by heat or pressure to form a horizontal ring 5 to locksidewall 29 to top plate.

Elastic sealer 10 has three sealing planes 16, 17 and 18 formed on thebottom of the elastic sealer. Sealing plane 18 is horizontal and sealingplane 17 is about 20 degrees. Sealing plane 16 tilts more upwards thanplane 17 from the inner to outer periphery of the elastic sealer and isabout 40 degrees relative to a horizontal surface or the bottom surfaceof the dish plate. Sealing planes 16 and 17 are formed at the bottom ofan outward protruded ring 25 of the sealer 10 to allow them to slopemore upward when interior surface 23 is more vertical. A ring-shaped gap26 is formed between ring 25 and sidewall 11 of the sealer 10 to enablethe sealing planes to be able to tilt even more upward. Elastomer andrubber materials have a durometer (shore A) of 20 to 60, preferably 25to 45 measured according to ASTM D-2240, are used for the sealer 10.Bottom surface 15 and ridges 15 and 27 convey a weight force of the lidor a vacuum force, which is to be discussed in FIG. 3, to sealing planes16, 17 and 18 in a controlled and gradually increased way to achieveairtight seal to interior surface 23 of the dish.

It was found that conventional gasket having either flat or roundsealing surface or the gasket taught by Hsieh in US publication number2009/0101535 having downwardly sloped sealing surface caused vacuum lossin days or even minutes when sealed to some dish plates, especially whenthe vacuum level in the closed chamber 22 is low. The lid 10 withelastic sealer 10 was found to maintain vacuum seal for much longertime, up to weeks and even months.

Knob 50 comprises a cylindrical body 73 received in an opening 34 formedon a recessed central section 75 of the top plate, an attachment screw77 having a base plate 56 to prevent knob 50 from moving out of theopening 34, a knob head 60 having horizontal protrusion 59 on the topend of body 73, and a O-ring 78. The cylindrical body 73 fitsfrictionally in opening 34. After placing the lid on a dish plate, onecan move the knob downward by pressing head 60, and can hold theprotrusion 59 to pull the knob up. The friction fit keeps the knob inthe up position (FIG. 1) without falling down to make the knob headreadily accessible. When knob 50 in the down position as shown in FIG. 1a, O-ring 78 seals the opening 34 and the knob mostly hides below thetop plate in closed chamber 22 to allow another dish plate 21 to stackon or over the top plate 30 as shown in FIGS. 1 and 1 a.

The ability to hide the knob when not needed not only helps savingstorage space in refrigerator and pantries but also enables a host orhostess for an outdoor party or a waiter or waitress in a restaurant tocarry several dishes at one time to speed up service and reduce workload. The airtight seal by the lid also provides other benefits such askeeps food fresher, keeps cooked food warm and prevent spill.

It is appreciated that in this and later embodiments of the invention,besides pans and plates, the lid or cover 1 can be used to seal othercontainers such as bowls, cups, bottles, canisters, chambers, cuttingboards, and surfaces on or in which other items may be supported.Besides food, other products such as household, commercial andindustrial items may be sealed in the container. It also appreciatedthat besides being round as in this and later embodiments, lid 1 mayalso adopt square, oval, rectangular or other shape. It also appreciatedthat the term top plate simply means that the plate is above the bottomof the container and may have any shape such as round, square,rectangular, ring, heart or oval shape. It further appreciated that themovable knob 50 may be used in existing glass or stainless lids for pansand other cooking devises to allow the hiding of the knob for storageand stacking.

In FIGS. 2 and 2 a, a first modified version of lid 1 of FIG. 1, showingonly the upper half of the lid, is provided. The modified Knob comprisesbody 73 a capped by head 60 a and connected by a screw 77 having a baseplate to a depressible protruded section 85 a of top plate 30, a valvechamber 35 having a base plate 129 and a valve opening 125, a elastic orrubbery valve sealer 127 above the base plate to cover the valveopening, a valve tube 74 fitted into the valve chamber to fix a rim 32of the sealer 127 to prevent the sealer from being pulled out of thevalve chamber, and a tubular opening 53 for receiving an evacuationdevice 84 shown in FIG. 2 b. Device 84 has a tube 83, and cut 87 at thelower end of tube 83 and a horizontal tube 76 connected to a vacuum pump(not shown). Valve sealer 127 has stem body 73 b and head 60 b extendedabove opening 53 to be readily accessible. Tubular opening 53 isdimensioned to fit tightly to tube 83 of device 84 to prevent tube 83from falling or moving during evacuation. Head 60 b and stem 73 b ofvalve sealer 127 are dimensioned to be receivable inside the tube 83.Part of the rim 32 of the sealer 127 is not fixed by valve tube 74 toallow one to pull the head 60 b to move the unfixed part of the valvesealer up 10 to 100 degrees, preferably 30 to 75 degrees to wash orclean the space between base plate 129 and sealer 127.

Unlike the lids in Seal-A-Meal® or FoodSave® vacuum containers whereone's hand has to hold an evacuation device steady during evacuation,lid 1 enables hand-free evacuation. One inserts tube 83 of the device 84into the tubular opening 53 to fit tightly and the stem body 73 b andhead 60 b are automatically received inside tube 83. The vacuum pullsvalve sealer 127 up to open valve opening 125 and cause the closedchamber 22 to the evacuated (FIG. 2 a). As vacuum develops in chamber22, depressible protruded section 85 a is pulled down by vacuum to forma recessed section 85 b to receive and hide knob 50 below the top plate30, allowing another dish plate (not shown) to sit on or stack over thetop plate. After device 84 is removed, sealer 127 falls to base plate129 to seal valve opening 125 to prevent vacuum loss in the closedchamber 22. To release the vacuum, one just pulls head 60 b upward toopen valve opening 125.

The depressible protruded section 85 a may be designed to stay in theprotruded form when there is no external force, enabling a small vacuumto be generated in closed chamber 22 by pressing knob head 60 a. Whenthe knob head is pressed, the protruded section 85 a becomes recessedsection 85 b and a positive pressure is produced in the closed chamberto push elastic sealer 127 up to release the pressure. When the knobhead is released, the recessed section 85 b tries to go back to theprotruded form and produce a vacuum, which in turn pulls the valvesealer down to close the valve opening 125 and prevents the recessedsection 85 b from returning to the protruded form 85 a.

Although the lid of FIG. 2 has addressed most problems of existing lidsdiscussed in the Background of the Invention, it still has severalproblems. First, the valve opening 125 sealed by elastic sealer 127often leaks because of food debris or dusts trapped between the valvesealer and the base plate 129. Second, only about 60 to 70% amount ofair in closed chamber 22 may be removed even with evacuation device 84since the affordable pumps can only remove 60 to 70% of air. Third, thetop plate 30 and sidewall 29 need to be thick and strong to stand thevacuum without breakage, making the lid heavy and expensive to make.Forth, the lid cannot seal containers smaller than the lid.

FIGS. 3 to 3 c show a second modified version for the lid of FIG. 1 toresolve the above problems. The improved lid comprises a first top plate30 a having an opening 34 and lip 33, a second top plate comprising anelastic membrane 30 b adapted to generate a vacuum in closed chamber 22and to convert the vacuum to a downward force to apply to the elasticsealer 10 to preserve the airtight seal and vacuum, a knob 50 connectedto the second plate 30 b and movable in opening 34 among variouspositions shown in FIGS. 4 to 4 d, and a membrane lock 31 for locking aperipheral section 7 of the elastic membrane to sidewall 29. The opening34 is large enough to allow a hand to pass through to move knob 50 froma position below the top plate to a position above the plate, which isto be discussed later in FIGS. 4-4 d. The top surface of the secondplate or elastic membrane 30 b is in contact with the first plate 30 awhen the knob is not in use or at a top position. Such contact makes thefirst and second plates look and function as one plate in dishwashers toprevent foreign matters from entering between the plates. An unexpectedbenefit for such contact is that the product life and the ability of thelid to maintain the vacuum over the life were significantly increased.

In the lids (Keepeez®) based on applicant's U.S. Pat. No. 7,594,586, itwas found that the elastic membrane tended to separate from the sidewall or rigid rim. Membrane lock 31 has resolved this problem, and itcomprises a first lock formed on top plate 30 a and having a first ridge8 and a first channel 2 for receiving the elastic membrane and a secondlock formed on sidewall 29 and having a second ridge 3 and secondchannel 9 also for receiving the elastic membrane. The second ridge 3 isadapted to fit into the first channel 2, and the first ridge 8 isadapted to fit into the second channel 9. The first and second ridgesare adjacent to each other and separated only by a vertical section ofthe elastic membrane 30 b. It is believed that the dimensionalvariations of elastic membrane 30 b, sidewall 29 and plate 30 a, whichare believed to cause the membrane separation from the rigid rim in thelids based on U.S. Pat. No. 7,594,586, become canceled out in themembrane lock 31, thus avoiding the membrane separation problem.

Knob 50 comprises knob body 73 having a base 45, a cylindrical chamber51 and a sidewall 35, an inner body 37 having a base 36 and sidewall 43adapted to fit tightly into chamber 51 to sandwich the elastic membranebetween sidewalls 35 and 43 and between bases 36 and 45, a knob head 60having horizontal protrusion 59, a first tube receiving opening 54 and arecession 57 above to reduce the height of the opening 54, a valve shaft55 having a top end affixed to the knob head and a lower end connectedto a valve sealer 42, a pair of plate-shaped springs 61 a and 61 b, eachhaving one end connected to sidewall 35 and another end connected to thevalve shaft, and a valve opening 80 formed in inner body 37 forcommunicating the closed chamber 22 with atmosphere. Protrusion 41 onthe valve shaft prevents the valve sealer 42 from slipping out. One ormore air channels 44 are formed on base 36 to direct air to valveopening 80 when knob 50 reaches the food. The base 45 fits into opening33 of the first top plate snugly to stabilize the knob, and the knob isprevented from moving out of the opening 33 by lip 34.

A protrusion 46 on the inner surface of sidewall 35 fits into acorresponding recession on the outer surface of sidewall 43 to preventthe sidewalls 35 and 43 from separation. A membrane scar 49 is formed atan edge of the elastic membrane 30 b to cause the membrane to bepermanently affixed to sidewalls 35 and 43. The scar 49 is formed byproducing a hole on a section of the elastic membrane above inner body37, and heating the membrane around the edge of the hole to cause themembrane to bead and progress to the area or junction where the sidewall43 of inner body 37 meets the sidewall 35 of knob body 73.

Valve opening 80 has a valve sidewall 79 dimensioned to form africtional fit to the valve sealer to cause an airtight seal between thevalve sidewall and valve sealer to allow the valve sealer to completelyclose the valve opening. Valve sealer 42 is adapted to move up and downfrictionally in valve opening 80, and cleans the valve sidewall 79 as itmoves. A cylindrical extension 40 is formed above the valve sidewall forreceiving and guiding the movement of the valve sealer. Three verticalchannels 47 (FIGS. 3 & 3 a) are formed on the sidewall 38 of theextension 40 to reduce the friction when the valve sealer moves from thevalve opening into the extension. When the valve sealer moves from thevalve opening into extension 40, a partial loss of the frictional fit isresulted, which in turn forms an air passage 58 at the bottom end ofchannel 47 to allow atmospheric air to enter chamber 22 via an opening53 on the plate-shaped spring 61 b, a ring-shaped chamber 48, and valveopening 80 (FIG. 4 b).

Unlike the valve in the prior art lid or in FIG. 6, the tube receivingopenings 53 and 54 of the knob are positioned upstream of the valveopening 80 and open up the space above the valve sealer 42 for directaccess to cleaning liquid or water and does not create any dead ordifficult to clean space in the valve 50. Tube receiving openings 53 and54 are dimensioned to receive tube 83 of the evacuation device 84 ofFIG. 2 b to allow a vacuum pump to evacuate the closed chamber 22. Theopening 54 is sized to allow device 84 to interact and push knob head 60down, therefore moving valve shaft 55 and valve sealer 42 down, to causeat least partial loss of the friction fit and the formation of airpassage 81 (FIG. 4 d) when tube 83 of the device is inserted into theopenings 53 and 54. Opening 53 fits to tube 83 tightly to lock theposition of the knob head.

An opening 67 is formed on the top wall 66 of the cylindrical extension40 and dimensioned to receive and allow movement of the shaft 55therein. An opening 69 is formed between the plate-shaped springs 61 aand 61 b, and also dimensioned to receive and allow movement of theshaft 55 therein, which causes the valve shaft and thus the valve sealer42 to be connected to the springs 61 a and 61 b. A space or gap 68 isbetween the springs 61 a and 61 b to enable independent movement of thesprings 61 a and 61 b. A stop plate 68 is formed on shaft 55 to sandwichsprings 61 a and 61 b between the bottom of the knob head 60 and thestop plate as well as to enable the knob head to pull the springs 61 aand 61 b upwards as shown in FIG. 4 b to open the valve opening 80 andproduce the air passage 58. A seal sleeve 62 is attached around the topend of the sidewall 35 to seal to the knob head 60 when the knob head ispushed down as shown in FIG. 4 d.

The springs 61 a and 61 b are sufficiently long to allow the valve shaftto move sufficient distance to cause the valve sealer 42 either to moveout of the valve opening 80 to lose all the frictional fit between thevalve sealer and the valve sidewall 79 and produce an air passage 81 asshown in FIG. 4 or lose part of the frictional fit to produce airpassage 58 as shown in FIG. 4 b. The springs are also sufficientlystrong to overcome the friction force of the frictional fit to cause thevalve sealer to return into the valve opening 80 after the valve sealeris moved to cause the loss or partial loss of the frictional fit toproduce the air passage 81 or 58. The valve opening 80 may have adiameter between about 2 mm and 20 mm, preferably between 5 mm and 10mm. To prevent leakage during the storage due to aging, accidentalcontact or touching, the motion sealing distance of the valve sealer 42,which is the maximum distance the valve sealer can move in the valveopening 80 towards the container without causing any air passage to formbetween the closed chamber and atmosphere, is normally between about 0.5mm to 15 mm, and preferably longer than 1 mm and 7 mm.

Knob 50 in FIGS. 3-9 has several unique features compared with othervalves. First, the valve sealer 42 keeps the valve opening 80 sealedeven when the valve sealer or valve shaft is moved a certain distance aslong as the distance is smaller than the motion sealing distance, thusmaking knob 50 much less prone to leakage than other valves that leakfluid even with a very slight move of the valve sealer. Second, thevalve sealer 42 swipes off any dust, food or other foreign matters onthe sidewall 79 of the valve opening, i.e. on the sealing surface, whenthe sealer moves up or down during normal use. This enables the knob orvalve to be self-cleanable, which is critical to the reliability of thelid. Third and also importantly, the valve sealer is allowed to moveamong a first position in which the valve sealer forms an airtight sealto the valve opening 80, a second position in which the valve sealer isat least partially above the valve opening to form a first air passage58 between the closed chamber and atmosphere, and a third position inwhich the valve sealer is at least partially below the valve opening toform a second air passage 81 between the closed chamber and atmosphere.The knob head 60 of the lid allows one to press to move the valve shaft55 and thus the valve sealer 42 down to form the air passage 58 to allowair to be removed from closed chamber 22. The knob head 60 also allowsone to pull to move the valve shaft 55 and thus the valve sealer 42 upto form air passage 58 to allow air to enter the closed chamber tofacilitate the removal of the lid from the container.

In FIG. 3 and other exemplar embodiments of the invention, it isappreciated that an extension similar to the cylindrical extension 40may be formed at the lower end of the valve opening 80. It is alsoappreciated that the openings 67 and 69, the horizontal cross section ofthe valve shaft 55 and the valve opening 80 may have oval, square orother non-circular shape to prevent any mis-alignment between openings53 and 54. It is also appreciated that the knob may adapt any shapessuch as oval, triangular, square, rectangular, star and heart shapesbesides the round shape. It is further appreciated that the first plate30a may adapt a ring shape and the opening 34 is larger than base 45 ofthe knob body 73. It is still further appreciated that knob head 60 andother non-essential parts may be minimized or even removed and the knobwork just as a valve with its sealing surface self-cleanable during use.

To use lid 1, one checks whether the container is larger or smaller thanthe lid. If the container is larger, one holds knob 50 to place elasticsealer 10 on interior surface 23 of the container. Before use, the knobis above opening 34 of plate 30 a with the base 45 resting therein in afirst or a non-use position (FIG. 3), thus being readily accessible forhandling and air evacuation through the knob. To produce vacuum topreserve food 20, one presses knob head 60 to move knob 50 in opening 34downward to a second or a storage position below or partly below opening34 shown in FIGS. 4 and 4 a. The base 45 of the knob pushes the secondplate or elastic membrane 30 b connected to the knob down to force airabove food 20 out via air passage 81, opening 80, channel 47, chamber 48and openings 53 and 54. Pressing knob head 60 causes springs 61 a and 61b to bend and valve sealer 42 at the end of valve shaft to move againstthe friction fit out of valve opening 80 to produce passage 81 (FIG. 4).When the knob head I released, springs 61 a and 61 b pushes the knobhead, valve shaft and the valve sealer up to close valve opening 80 toset the knob at the storage position as shown in FIG. 4 a to preservethe vacuum in the chamber 22. To open the valve opening 80, one simplypulls knob head 60 upwards to move the knob to a third position, causingsprings 61 a and 61 b to bend and the valve shaft 55 and valve sealer 42to move up into cylindrical extension 40 to produce air passage 58 (FIG.4 b). While the knob is at the third position, which is between thefirst and second positions, air continues to enter chamber 22 viapassage 58 and as a result causes the third position of the knob tochange until the knob reaches the first position.

If the container is smaller than the lid (FIG. 4 c), one places the topplates 30 a and 30 b over the rim 24 of container 21. The bottom surfaceof the elastic membrane 30 b is smooth and has a peripheral section 7accessible to the container to form an airtight seal to rim 24, enablingthe lid to seal containers smaller than the lid. To remove air andcreate vacuum, one presses the knob 60 in a way similar to that shown inFIG. 4. To release the vacuum and remove the lid, one pulls the knob ina way similar to that shown in FIG. 4 b. The knob 50 in this and otherembodiments of the invention may be pressed down more or less to removemore or less air, thus creating higher or lower vacuum level. Thepositions of the knob relative to the opening 34 or lip 34 of the plate30 a therefore indicate the vacuum level below the lid. For examples,when knob head 60 is positioned far above lip 33, the vacuum level islow, when it is leveled with the lip, the vacuum level is medium, whenit is far below the lip, the vacuum level is high.

Unlike existing vacuum lids where the lid can not change shape anddimension, the lids in FIG. 3, FIGS. 5 and 7 have the second top plate30 b adapted to conform to the shape of the food, thus allowing a lotmore air above the food to be evacuated by evacuation device 84connected to a vacuum pump (not shown). To use, one insert the tube 83of the device into the tube receiving openings 53 and 54 to push theknob head 60 down, which in turn bends the springs 61 a and 61 b andmoves the valve shaft 55 and valve sealer 42 down to form air passage81. The seal sleeve 62 seals the valve body 73 to knob head 60, and thetight fit between the tube 83 and tube receiving opening 53 prevents theknob head from moving up by the springs 61 a and 61 b. As the vacuumpump draws air out of the closed chamber 22 via passage 81, valveopenings 80, channel 47, chamber 48 and tube 83, the elastic membranebecomes stretched and moves down to cover and conform to the shape ofthe food 20 (FIG. 4 d).

In FIG. 3 d, an improved membrane lock 31 is provided for the lid 1 ofFIG. 3. Only part of sidewall 29 and part of the first and second plates30 a and 30 b are shown. The sidewall 29 is tilted inwardly toward thecenter of lid and the membrane lock 31 is protruded inwardly from thesidewall 29 towards the center of the lid to enable a plurality of thesame size lids to stack into each other. A small opening 162 is formedon the first plate located near the sidewall 29 and apart from theopening 34 and knob 50 to allow fluid such as water or air between thefirst and second plates to pass through. The improved membrane lock 31comprises a first lock 165 formed on top plate 30 a and having a firstridge 171 and a first channel 163 for receiving elastic membrane 30 band a second lock 167 formed on sidewall 29 and having a second ridge164 and second channel 166 for receiving the elastic membrane. Thesecond ridge 164 is adapted to fit into the first channel 163, and thefirst ridge 171 is adapted to fit into the second channel 166. The firstchannel 163 causes the bottom part of the first plate to be wrapped bythe elastic membrane to prevent the membrane from moving out of channel163. Like the membrane lock in FIG. 3, to prevent the elastic membranefrom separation from the lock 31, the first and second ridges areseparated only by a vertical section of the elastic membrane 30 b.

The first channel 163 on plate 30 a is a continuous round channel. Butthere are a plurality of second channels 166 on sidewall 29 around thesecond ridge 164 and a plurality of first ridges 171 on plate 30 aaround the first channel 163 adapted to enter the plurality of secondchannels 166 when the second ridge 164 enters the first channel 163.Each first ridge 171 comprises a left ridge 171 a having a hooked end170 a, a right ridge 171 b having a hooked end 170 b, and a gap 172between the left and right ridges (FIG. 3 e). A side channel 168 isformed below each second channel 166 for receiving the hooked ends ofthe first ridge. The width of each second channel 166 is smaller thanthe width of each side channel 168, and is sized to require the left andright ridges 171 a and 171 b to bend toward each other in order for thehooked ends 170 a and 170 b to pass through. At least one of the firstridge 171, second channel 166 and side channel 168 may have sharpelements to break a part of the elastic membrane 30 b when the firstridges 171 are forced into the second channels 166. The breaking of theelastic membrane is found to prevent the separation of the membrane fromthe membrane lock. It is appreciated that it is possible to form thesecond channel and ridge on the first lock 165 and form the firstchannel and ridge on the second lock 167.

FIGS. 5 to 5 c provides a third modified version of the lid of FIG. 1with an improved elastic sealer 10 having mini gaskets 93 connected tosealing planes 16, 17 and 18. Though the elastic sealer of FIG. 1 formslonger lasting seal than other lids, the seal is not enough for sincemost kitchen containers have minor indented or protruded areas on theirinterior surface 23 and are not perfectly round. In addition, even if acontainer is perfectly round, it still appears oval or non-round to thelid if the lid is not centered in it. Mini gasket 93 comprises a sealingmembrane 94 located below and apart from the bottom of the elasticsealer and having a first end 105 connected to the bottom surface of theelastic sealer and a second end 106 movable relative to the elasticsealer. The sealing membrane 94 is sloped or tilted at an angle betweenabout 1 to 89 degrees, preferably about 2 to 80 degrees, to thehorizontal plane to achieve long lasting seal. Here the sealing membraneadapts the shape of a sloped letter I. It is found even longer lastingseal is achieved by sloping or tilting the sealing membrane outwards sothat the second end 106 is closer to the outer periphery of the elasticsealer than the first end 105 (FIG. 5). Part of the sealing membrane maybe sufficiently thin to cause it collapse and a part of it to touch thebottom surface of the elastic sealer by the weight of lid when the lidstands on the container, thereby facilitating the vacuum formation.

FIG. 5 c shows an improved version of the mini gasket 93 in which thesealing membrane 94 has a sealing rim 124 at the second end 106. Thesealing rim is thicker or fatter than the sealing membrane or at leastthan the part of the sealing membrane adjacent to the sealing rim. InFIG. 5 d, sidewall 29 has a sloped bottom surface 15 so that the innerface of the sidewall is taller than the outer face, which was found toprevent food from entering between sidewall 29 and elastic sealer duringuse. FIG. 5 d also shows another improved mini gasket 93 in which thesealing membrane 94 comprises a leg 123 and a foot 122 to seal to theinterior surface 23 of the container. Here the sealing membrane 94adapts letter L shape. It is appreciated by tilting leg 123 of FIG. 5 c,the sealing membrane 94 adapts a sloped V shape; by curving leg 123 andfoot 122, the sealing membrane adapts C shape; by moving the foot 122about 50% to the left of leg 123, the sealing membrane adapts aninverted T shape; by moving the foot 122 about 50% to the left of leg123 and curving the foot 122, the sealing membrane adapts an inverted Yshape; by adding a leg to the second end 106, the sealing membraneadapts a letter U shape. Since the combination and variation of leg 123and foot 122 has the effect of a sloped sealing membrane, the above L,sloped V, C, inverted T, inverted Y, and U shaped sealing membranes 94are all considered generally sloped. It is also appreciated that thesealing membrane may be formed on or attached to the bottom of a plasticor metal ring to form the elastic sealer. It is also appreciated thatelastic sealer 10 may need only one mini gasket or sealing membrane toachieve enough seal to the interior surface 23. It is furtherappreciated at least part of the sealing membrane designed to contactinterior surface 23 is made sufficiently thin to conform to the minorindents and protrusions on the interior surface, and has a thicknessless than about 1.5 mm, preferably less than 0.75 mm, and mostpreferably less 0.5 mm.

The sidewall 29 is formed from a stainless steel sheet and the top plate30 a is made from glass. A channel 88 is formed at the top part 97 ofsidewall 29 to receive a ring 90 and to sandwich the peripheral section7 of the elastic membrane. Glass plate 30 a is placed over ring 90 andthe top end 91 of the sidewall is rolled over glass plate 30 a to affixthe elastic membrane with scar 92 formed at the periphery of themembrane. Like knob 50 of FIG. 3, the modified knob comprises knob head60, knob body 73 and inner body 37 for sandwiching the elastic membranethere between. Knob body 73 has a top chamber 57 to receive knob head60. A recession 52 is formed on the rim of chamber 57 to facilitate theevacuation of closed chamber 22 by pressing the knob head. Knob head hasa sidewall 102 received and movable in the ring-shaped chamber 48. Afirst spring 100 is compressed between the top wall 66 of cylindricalextension 40 and the valve sealer 42 for moving the valve shaft 55 andvalve sealer 42 down and a second spring 101 is compressed between theknob head and top wall 66 for moving the valve shaft and valve sealerup. The first and second springs are selected to keep the valve sealerin the valve opening 80 during storage or when the lid is not in use.The first spring 101 is preferably stronger or has a larger spring forceconstant than the second spring 100 to increase the sealing reliabilityof the knob 50 and lid during vacuum storage.

Besides glass plate 30 a and elastic membrane 30 b, top plate 30 furtherhas a shield 143 below and connected to the base 36 of inner body. Theshield is in contact with the elastic membrane prior to use and movesaway or more apart from the elastic membrane as the air in the closedchamber 22 is being evacuated (FIG. 5 a). It is larger than base 45 ofthe knob body and has a plate 144 and a plurality of openings 146. Theshield was found to prevent the elastic membrane from being damaged bysharp bones or shells in the food when one presses knob to push themembrane against the food or when the lid is connected to a vacuum pump.An unexpected benefit of the shield 143 is that it prevents the elasticmembrane 30 from damages by microwave oven, especially when lid 1 coversfood containing tomato sauce or oil, which has been a major problemassociated with Keepeez® lids taught by applicant in U.S. Pat. No.7,594,586. The shield is preferably smaller, most preferably 5 mm to 40mm smaller, than the sidewall 29 to facilitate the cleaning of the lid.

To use, one simply presses the knob head 60 to compress the secondspring 101, thus moving the valve shaft 55 and valve sealer 42 down toproduce air passage 81,and to push the elastic membrane 30 downward toforce air out of the closed chamber 22 via the air passage 81 (FIG. 5a). The downward movement of the elastic membrane causes the shield 143connected to the membrane and knob 50 to move down with the membrane asair is removed from chamber 22. If one desires to remove more air forthe food, an evacuation device 84 (FIG. 5 b), which has a tube 83 toseal to the top chamber 57 and the a pin 107 to push the knob head 60,may be inserted into the top chamber 57 of the knob 50.

FIG. 6 shows a fourth modified version of the lid of FIG. 1. Compared tolid of FIG. 5, the top plate 30 here has only one layer and the innerbody 37 functions as knob body 73 and is formed directly on the topplate. A tubular channel 112 is formed in valve shaft 55 with a top endconnected to a chamber 115 and lower end 111 connected to closed chamber22. Tube receiving opening 54 is formed on a disc 117 sealed to chamber115. A ball sealer 120 is pushed against disc 117 by a spring 116 toclose opening 54. The sidewall 29 is made from stainless steel orplastics and has a plurality of elastic pleats 119 a and 119 b adaptedto collapse or change in height when pressed to expel air out of thechamber 22 and to have a memory to rebound or return to its originalheight when not pressed, thus generating vacuum in the closed chamber.

Similar to the lid of FIGS. 5 and 5 a, one presses the knob head 60 topush the valve shaft 55 and valve sealer 42 down produce air passage 81(not shown). The knob head 60 and spring 101 convey the pressing forceto the sidewall 29 via knob body 37 and top plate 30 to compress theelastic pleats 119 a and 119 b to force air out of chamber 22 via theair passage 81 (not shown). When not pressed, the knob head 60 is pushedup by spring 101 to cause the shaft 55 and valve sealer 42 to move upand close the valve opening 80; the compressed elastic pleats try toexpand, thereby producing a vacuum in closed chamber 22. To releasevacuum and lift up the lid 1, similar to that shown in FIG. 4 b, oneholds the protruded part 59 or knob head 60 and pulls the knob up, whichcauses the valve shaft 55 and valve sealer 42 to move up into thecylindrical extension 40 to produce air passage 58 (not shown) to allowair to enter chamber 22 and the compressed pleats to expand and returnto its original height.

To evacuate air with evacuation device 84 of FIG. 2 b, one inserts tube83 into tube receiving opening 54 to push ball sealer 118 down toevacuate air from the closed chamber 22 via channel 112.

A fifth modified version of the lid of FIG. 1 is presented in FIGS. 7 to7 c. The improved lid comprises a first plate 30 a, a sidewall 29connected above the first plate and having bottom surface 15 about inthe same plane as the bottom surface of the first plate and a channel 2,and a second plate or elastic membrane 30 b. Membrane 30 b comprises aperipheral section 7 having a smooth lower surface for enabling the lidto form a seal to the rim 24 of container 21 in a way similar to thatshown in FIG. 4 c. The peripheral section 7 has a mostly flat section 18that covers or wraps bottom surface 15 of the sidewall 29 to formelastic sealer 10 for enabling the lid to form an airtight seal to theinterior surface 23 of container 21. This means, like lid of FIGS. 3 and5, the lid can seal containers both smaller and larger than the lid. It,however, has much lower cost than the lid of FIGS. 3 and 5 since itselastic sealer 10 is just a peripheral section of the elastic membrane30 b and its sidewall 29 is just a part of the first plate 30 a. Theperipheral section 7 located close to sidewall 29 is sloped or tilteddownward from sidewall 29 to knob 50 at an angle relative to ahorizontal plane when the lid is not in use or not applied to acontainer (FIG. 7). The lower surface of the first plate 30 a is alsotilted downward from sidewall 29 to the center. The angle or slope isabout 5 to 75 degrees, preferably 10 to 60 degrees. Such slope was foundto improve the seal to the rim 24 of the container, enables the elasticmembrane to seal to the interior surface 23 when the slope or angle islarge, and help removing fluid between the plates 30 a and 30 b.

The peripheral section 7 also has a sloped part 17 that covers apredetermined height of the outer surface of the sidewall 29 and isaccessible to the interior surface 23 of the container to improve theseal to the container. The most outer part of peripheral section 7 isaffixed to channel 2 by a ring 82 and has scar 92 formed at theperiphery of the membrane. A fluid gap 19 is formed between the slopedpart 17 and the sidewall 29 to contain a layer of fluid such as air orliquid to further improves the seal of the elastic membrane to interiorsurface 23 of the container. The distance between the sidewall 29 andthe sections 17 and 18 of the elastic sealer 10 of the elastic membrane30 b contacting the bottom surface 15 and covering of the outer surfaceof the sidewall 29 is adapted to be changeable to enable the sections 17and 18 of the elastic membrane to better conform to the interior surface23 of the container to further improve the airtight seal.

The elastic membrane 30 b is stretched 1% to 50%, preferably 5% to 30%when or before the membrane is attached to the sidewall 29 by ring 82during the production or assembly of the lid, and is maintained in thestretched and tensioned condition when the lid is not in use or notapplied to a container. Such stretching facilitates the expelling offluid such as air and water if present between the first and secondplates 30 a and 30 b when the knob moves from a vacuum storage positionin which the knob is partly below the opening 34 or plate 30 a to anon-use position in which the knob is above or mostly above the opening34.

A problem discovered with the lid taught in applicant's U.S. Pat. No.7,594,586 is that after extensive heavy uses for months, a small percentof lids (e.g. about 4% depending on the age of the lids) developed smallleakage. It was tried to resolve this problem by doubling the thicknessof the membrane, for example from 0.05 mm to 0.1 mm. Only some limitedsuccess was achieved. In average, the percent of lids that developedleakage was reduced by about 30%, i.e. from about 4% to about 3% whenthe membrane thickness is doubled. It was found with surprise when theone elastic membrane were replaced by two identical elastic membranes inlid 1, the percent of lids that developed leakage was reduced by almost250%, i.e. from about 4% to about 1.5%. The improvement is almost 10times better than expected. As a result, it is preferred that theelastic membrane 30 b comprises a plurality of elastic membranes in onestack with their peripheral sections connected together to the sidewall29. Even more surprisingly, when the two membranes in lid lwere bondedtogether by heat, no leakage was found in almost 200 lids afterextensive heavy uses. This means the bonding process resolved theleakage problem, and bonded membranes with 2 or more elastic membranesbonded together by a bonding process such as calendaring, heat orpressing bonding, laminating or extrusion coating are preferred in lid1.

The improved knob 50 of FIG. 7 is simplified by removing the ring-shapedchamber 48 of the knob in FIGS. 3 and 5, and comprises knob body 73having an rim 109 for preventing the knob body from being pushed belowthe opening 34, inner body 37 having valve opening 80 and cylindricalextension 40 open to atmosphere via tubular openings 72 and 53 directlybelow tubular opening 54 on knob head 60, a valve sealer 42, and springs100 and 101 adapted to keep the valve sealer at least partly in thevalve opening 80 even when there is vacuum below the knob as long as theknob head 60 is not pressed or pulled. Cylindrical extension 40 iscovered by top wall 66 of knob body 73 having opening 67 to receivevalve shaft 55. Knob body 73 has is only slightly smaller than opening34 to allow the knob to move up and down in the opening and to preventforeign solids from entering the space between the first and secondplates 30 a and 30 b. After the knob is moved to a lower position inopening 34, a layer of static air 120 is formed between the first andsecond plates to provide heat insulation for the product 20 in closedchamber 20 (FIG. 7 c). It is appreciated that the first plate 30 a maybe connected to the upper part of sidewall 29 and is apart and above thesecond plate or elastic membrane 30 b. It is also appreciated that anairtight seal may be formed between the opening 34 and knob body 73 byan O-ring or seal gasket to preserve a vacuum between the first andsecond plates 30 a and 30 b after knob 60 is moved from a first unusedposition (FIG. 7) to a second sealed storage position.

To use, if the container 20 is larger than the lid 1, one places theelastic sealer 10 on the interior surface 23 and press the knob head 60to produce air passage 81 to evacuate air in chamber 22 (FIG. 7 c) andrelease the knob head to allow valve sealer 42 to return into valveopening and allow a vacuum to form in the chamber. To remove the lid,one pulls the knob head in a similar way shown in FIG. 4 b. If thecontainer is smaller than the lid, one places elastic membrane 30 b overthe rim 24 of the container in a similar way shown in FIG. 4 c. Toevacuate via a pump, one insert the tube 83 of device 84 of FIG. 2 binto openings 54, 53 and 72 to press knob head 60 down. Tube 84 fitsfrictionally to openings 53, 54 and 72 to keep knob head down to causeO-ring 108 to seal opening 67 during the evacuation even after onereleases knob head.

An improved lid of FIG. 7 is shown is FIG. 7 d. The channel 2 of theimproved lid faces sideways to allow a plastic or metal sleeve 82 to bepushed in to sandwich and affix the peripheral section of the elasticmembrane to the sidewall 29, therefore makes all of the sloped section17 of the elastic membrane readily accessible to the interior surface ofthe container for improved sealing. A shield 143 having a disc plate 144below the base plate 45 of the knob 50 is connected to inner body 37 forprotecting the elastic membrane in a similar way as the shield of FIG.5. The shield also has a rim 121 to sit on countertop or table surfacewhen lid is not in use. The base plate 45 is smaller than the opening 34to expose part of the elastic membrane 30 b to facilitate cleaning. Theelastic membrane 30 b is tilted or sloped first downward and then upwardfrom sidewall 29 to the center of the lid. A chamber 128 is formed belowthe base plate 45 and disc plate 144. The top end of the spring 101 isimmobilized to the bottom end of the knob head 60 and the lower end ofthe spring 101 is immobilized to plate 66 of the knob body so that thespring 101 is not only able to pull the valve sealer 42 back into thevalve opening after the knob head is pressed but also able to push thevalve sealer back into the valve opening after the knob head is pulledup. Such immobilization of the spring's ends not only saves the cost ofspring 100 but also allows the knob to be shorter to facilitate stackingand storage.

In FIGS. 8 and 8 a, a sixth modified version of the lid of FIG. 1 isprovided. Here the sidewall comprises an outer sidewall 28 a and aninner sidewall 28 b located a predetermined distance from the outersidewall. The sloped section 17 of the elastic sealer 10, i.e. theperipheral section of the elastic membrane 30 b, is positioned betweenthe outer and inner sidewalls 28 a and 28 b. The membrane lock 31 has achannel 9 and ridge 8 to sandwiching the outer part of the membrane. Astainless steel cover 149 covers the sidewall 29 and has a top cover 30c to cover the first plate 30 a, an opening 141 on the top cover forimmobilizing a elastomer or rubber ring 199 in tubular opening 53 toincrease the friction to tube 83 when device 84 of FIG. 2 b is inserted,and a bottom cover 148 rolled over the bottom of outer sidewall 28 a. Apassage 162 is formed in first plate 30 a to allow air to enter andleave the fluid gap 19 to facilitate the sealing of the inner surface 23to the sloped section 17 of the elastic sealer 10. To use, one insertsthe sloped section 17 of the elastic sealer 10 into the container 21,press the knob head 60 to push the valve shaft 55 and valve sealer 42out of valve opening 80 to produce an air passage to evacuate air in thecontainer, and release the knob head to allow the valve sealer to closethe valve opening to maintain the vacuum in the container (FIG. 8 a). Toremove the lid, one just pulls the knob head up as described in FIGS. 3to 7.

When testing the lid of FIG. 8, it was discovered that the slopedsection 17 of the elastic sealer 10 could form a long lasting airtightseal to the container even when the knob 50 is removed. Without knob 50,one just inserts the sloped section 17 of the elastic sealer 10 into acontainer and presses the top plate 30 c to deform the sloped section 17till most or all of the sloped section 17 of the elastic sealer hasentered the container. It is discovered that the lid works the best whenthe sloped section 17 is sloped or tilted at an angle larger than15degrees, preferably larger than 45 degrees and most preferably morethan 60 degrees relative to a horizontal plane or to the horizontalplate 30 a. The lid was found to rebound a little after being released,and such rebounding is reduced or eliminated when the passage 162 ispresent and/or the slope angle is about 60 degrees or more. It isappreciated that the lids of FIGS. 7 and 7 d can also form a longlasting airtight seal to the container without knob 50. It is alsoappreciated that elastic membrane 30 b of FIG. 8 may be replaced by anelastic gasket or sealer 10 adapted to fit between the outer and innersidewalls 28 a and 28 b and comprises a horizontal top base 120 forcontacting top plate 30 a and sidewall 29, a bottom ring 18 and thinsealing membrane 17 connected to the top base and bottom ring (FIG. 8b). The sealing membrane 17 is sloped at an angle of preferably largerthan 15 degrees, more preferably larger than 45, and most preferablylarger than 60 degrees relative to a horizontal plane or the horizontaltop base 120. The sealing membrane 17 is preferably less than 1.5 mm andmore preferably less than 0.7 mm to improve the airtight seal to theinterior surface 23 of a container.

In FIGS. 9 to 9 b, a seventh modified version of the lid of FIG. 1 isprovided. This modified lid is similar to that of FIG. 8 but has arevised knob 50 with a smaller knob head 60. The revised knob comprisesa body 37 having valve opening 80 and a chamber 150, a knob head 60 havea tubular body 151 fitted to and movable in chamber 150, an outwardprotrusion 152 to prevent the knob head from moving out of the chamber150, a tubular opening 54, an inwardly protruded top lip 155 and arecession 52 on the top lip, and a valve shaft 55 having a top cylinder156 movable within the tubular body 151 and a lower end 41 to affixvalve sealer 42. The top cylinder 156 is prevented from moving out ofthe tubular body 151 by the inward protrusion 155 and has a throughopening 158.

To vacuum seal, one inserts the sloped section 17 of the elastic sealer10 of the elastic membrane 30 b into container 21 to seal to itsinterior surface 23, press the knob head 60 to cause valve shaft to pushvalve sealer 42 out of the valve opening 80 to produce air passage 81 toevacuate air (FIG. 9 a), and release the knob to allow the spring 100 toreturn the valve sealer into the valve opening 80 to seal and maintainthe vacuum. To vacuum more air with a pump, one inserts the tube 83 ofdevice 84 of FIG. 2 b into opening 54 to press top cylinder 156 andvalve shaft 55 to push valve sealer 42 out of the valve opening 80 toproduce air passage 81 (FIG. 9 b). When the tube 84 is removed, spring100 pushes top cylinder 156 up to return valve sealer 42 into valveopening 80 to seal and preserve the vacuum in the container. To releasevacuum, one presses knob head 60 just enough to push the valve sealer 42out of the valve opening 80. It is appreciated that a protrusion 59 ofFIG. 8 may be formed on knob head 60 of FIG. 9 to allow one to pull theknob head up to release the vacuum and lift the lid off the container.

The scope of the invention is obviously not restricted or limited to theembodiments described by way of examples and depicted in the drawings,there being numerous changes, modifications, additions, and applicationsthereof imaginable within the purview of the claims.

1. A lid for sealing a container comprising: a top plate; a sidewallconnected to the top plate; a knob for facilitating the removal of thelid from the container; wherein at least one of said top plate andsidewall is adapted to seal to the container to form a closed chamberbetween said top plate and the container; and wherein at least part ofsaid knob is adapted to change position relative to the container afterthe lid is applied to the container.
 2. A lid as defined in claim 1wherein said knob comprises a body, a base plate to prevent said bodyfrom separating from the top plate, and a head protruded out of saidbody horizontally for one to hold and move said knob between a firstposition in which said knob is at least partly above said top plate tomake said knob readily accessible and a second position in which saidknob is at least partly below said top plate to allow a second containerto sit on said top plate, thereby allowing stacking of containers.
 3. Alid as defined in claim 2 wherein said top plate comprises at least oneof a recessed section and a depressible section to which said knob isconnected.
 4. A lid as defined in claim 1 wherein said top platecomprises an opening adapted to allow said knob to move in said openingbetween a first position in which said knob is at least partly abovesaid opening and a second position in which said knob is at least partlybelow said opening.
 5. A lid as defined in claim 4 wherein said topplate comprises a first plate on which said opening is formed and asecond plate to which said knob is connected, said knob being adapted tomove in said opening between said first and second positions.
 6. A lidas defined in claim 5 wherein said second plate is in contact with saidfirst plate when said knob is at said first position to prevent foreignmatters from entering between said first and second plates.
 7. A lid asdefined in claim 6 wherein said second plate comprises an elasticmembrane and said first plate has a lower surface adapted to cause atleast the peripheral section of said membrane to slope downward at adirection from said sidewall to knob, thereby improving the seal to thecontainer.
 8. A lid as defined in claim 6 wherein said second platecomprises an elastic membrane in a stretched and tensioned conditionprior to applying the lid to a container to facilitate the expelling offluid including at least one of air and water between said first andsecond plates when said knob moves from said second position to saidfirst position.
 9. A lid as defined in claim 5 wherein at least part ofsaid knob is sufficiently large to close said opening and allow a layerof air to form between said first and second plates to provide heatinsulation for a product in said closed chamber when said knob is atsaid second position.
 10. A lid as defined in claim 5 wherein said firstplate further comprises a second opening located close to said sidewalland apart from said knob to allow fluid between said plates to passthrough.
 11. A lid as defined in claim 5 wherein said knob comprises avalve opening and a valve sealer for closing said valve opening duringstorage when said knob is at said second position, said valve sealerbeing adapted to open said valve opening when said knob is at a thirdposition, said third position being between said first and secondpositions.
 12. A lid as defined in claim 5 wherein said opening issufficiently large to allow a hand to pass through and move said knobfrom said second position to said first position.
 13. A lid as definedin claim 5 wherein said opening is adapted to prevent said knob fromcompletely moving out of said opening at least in one of the upward anddownward movements of said knob.
 14. A lid as defined in claim 5 furthercomprising a seal gasket between said opening and knob body to maintaina vacuum between said first and second plates after said knob is movedfrom said first to said second position.
 15. A lid as defined in claim 1wherein said top plate comprises an elastic membrane having a peripheralsection and a membrane lock comprising a first lock having a first ridgeand a first channel for receiving said peripheral section and a secondlock having a second ridge and a second channel also for receiving saidperipheral section, wherein said first ridge is adapted to end saidsecond channel when said second ridge enters said first channel to locksaid peripheral section to said sidewall.
 16. A lid as defined in claim15 wherein said first and second ridges are separated only by a verticalsection of said peripheral section of said membrane to prevent saidmembrane from moving out of said channels.
 17. A lid as defined in claim15 wherein said second channel has a plurality of channels around saidsecond ridge and said first ridge has a plurality of ridges around saidfirst channel, each of said plurality of ridges having a wider endadapted to pass through each of said plurality of channels, said lockfurther comprising a side channel sized to receive said wider end ofeach of said plurality of ridges, wherein at least one of said sidechannel, said first ridge and said second channel is adapted to breaksaid elastic membrane.
 18. A lid as defined in claim 1 wherein said topplate further comprises a first plate having a channel and a secondplate having an elastic membrane, said channel being adapted to causesaid elastic membrane to wrap the bottom surface of said first plate toprevent said elastic membrane from moving out of said channel.
 19. A lidas defined in claim 1 wherein said top plate comprises an elasticmembrane and a membrane lock for locking said elastic membrane to saidsidewall, said sidewall being tilted toward the center of the lid toallow a plurality of said lids to stack into each other, said sidewallcomprising an inward protrusion at its top end for hosting said membranelock, thereby facilitate said stacking.
 20. A lid as defined in claim 1wherein said top plate comprises an elastic membrane, said membranecomprises a scar at an edge of said membrane to facilitate the attachingof said membrane to at least one of said sidewall and side knob.
 21. Alid as defined in claim 1 further comprises an elastic sealer connectedto said sidewall and adapted to form an airtight seal to an interiorsurface of a container.
 22. A lid as defined in claim 21 wherein saidtop plate comprises an elastic membrane adapted to generate a vacuum insaid closed chamber and further adapted to convert the vacuum to adownward force applied to said elastic sealer to maintain said airtightseal.
 23. A lid as defined in claim 22 wherein said elastic membrane hasa smooth lower surface accessible to a container to seal to the rim ofthe container, whereby said membrane allows the lid to seal containerssmaller than the lid and said elastic sealer allows the lid to sealcontainers larger than the lid.
 24. A lid as defined in claim 21 whereinsaid elastic sealer comprises a plurality of sealing planes havingdifferent angles relative to a horizontal surface, the outer sealingplane being adapted to tilt more upwards from the inner to outerperiphery of said sealer than the inner sealing plane.
 25. A lid asdefined in claim 21 wherein said sidewall has a bottom surface incontact with said elastic sealer to apply a force to said sealer tocause said airtight seal, said bottom surface being adapted to be sosloped that the inner face of said sidewall is taller than the outerface.
 26. A lid as defined in claim 21 wherein said top plate comprisesan elastic membrane, said elastic membrane having a smooth lower surfacefor enabling the lid to seal to the rim of a container and an outersection that covers at least part of the bottom surface of said sidewallto form said elastic sealer for enabling the lid to seal to the interiorsurface of a container.
 27. A lid as defined in claim 21 wherein saidsidewall is adapted to change in height when the lid pressed to expelair out of said closed chamber and to have a memory to return to itsoriginal height when the lid is not pressed, thereby generating a vacuumin the closed chamber.
 28. A lid as defined in claim 21 wherein saidelastic sealer comprises at least one mini gasket connected to saidelastic sealer to improve said airtight seal, said mini gasketcomprising a sealing membrane located below and apart from the bottomsurface of said elastic sealer.
 29. A lid as defined in claim 28 whereinsaid sealing membrane is adapted to collapse to cause at least part ofit to touch said bottom surface when the lid stands on the container.30. A lid as defined in claim 1 wherein said top plate comprises anelastic membrane and a shield below said membrane, said shield beingadapted to move away from said elastic membrane as air in said closedchamber is being removed.
 31. A lid as defined in claim 1 wherein saidknob comprises a valve opening for communicating said closed chamberwith atmosphere and a valve sealer, said valve opening having a valvesidewall of a predetermined length adapted to form a frictional fit tosaid valve sealer to cause an airtight seal, said valve sealer beingadapted to move in said valve opening to cause at least a partial lossof said frictional fit to form an air passage between said closedchamber and atmosphere.
 32. A lid as defined in claim 1 wherein saidknob comprises a valve opening for communicating said closed chamberwith atmosphere and a valve sealer, said valve sealer being adapted tomove among a first position in which said valve sealer forms an airtightseal to said valve opening, a second position in which said valve sealeris at least partly above said valve opening to form a first air passagebetween said closed chamber and atmosphere, and a third position inwhich said valve sealer is at least partly below said valve opening toform a second air passage between said closed chamber and atmosphere.33. A lid as defined in claim 32 wherein said knob further comprises aknob head adapted to be pressed to move said valve sealer to form saidsecond air passage, thereby allowing air in said closed chamber to beevacuated, and to be pulled to move said valve sealer to form said firstair passage to release the vacuum in said closed chamber, therebyallowing the lid to be removed from the container.
 34. A lid as definedin claim 1 wherein said top plate comprises a plurality of elasticmembranes in one stack with their peripheral sections connected togetherto said sidewall.
 35. A lid as defined in claim 34 wherein saidplurality of elastic membranes was bonded together by a bonding processto prevent the leakage of the elastic membrane after extended heavyuses.
 36. A lid for sealing a container comprising: a top plate; asidewall connected to the top plate; wherein at least one of said topplate and sidewall comprises an elastic sealer to seal to the containerto form a closed chamber between said top plate and container; andwherein said elastic sealer comprises a sealing membrane adapted tocontact and seal to an interior surface of the container, at least partof said sealing membrane being generally sloped at an angle relative toa horizontal plane when the lid is not in use or not applied to thecontainer.
 37. A lid as defined in claim 36 wherein said top platecomprises an elastic membrane adapted to cover at least part of a bottomsurface of said sidewall, said sealing membrane comprising the part ofsaid elastic membrane below said bottom surface of said sidewall.
 38. Alid as defined in claim 37 wherein the distance between said sealingmembrane and said sidewall is adapted to be changeable to improve saidairtight seal.
 39. A lid as defined in claim 36 wherein said top platecomprises an elastic membrane adapted to cover a predetermined height ofan outer surface of said sidewall, said sealing membrane comprising thepart of said elastic membrane outside said outer surface of saidsidewall.
 40. A lid as defined in claim 38 further comprising a layer offluid including at least one of air and a liquid between said sealingmembrane and said outer surface of said sidewall.
 41. A lid as definedin claim 36 wherein said elastic sealer further comprises a top baseadapted to contact at least one of said sidewall and top plate, saidsealing membrane being connected to said top base at an angle largerthan 15 degrees relative to the horizontal plane.
 42. A lid as definedin claim 36 wherein said top plate comprises a first plate and anelastic membrane below said first plate, said elastic membrane beingadapted to cover at least part of said side wall and at least part ofthe bottom surface of said first plate near said sidewall, said sealingmembrane comprising the part of said elastic membrane that covers saidsidewall or bottom surface of said first plate near said sidewall.
 43. Alid as defined in claim 42 wherein at least part of said sealingmembrane is sloped at an angle of at least 5 degrees relative to thehorizontal plane when the lid is not in use or not applied to acontainer.
 44. A lid as defined in claim 42 wherein at least part ofsaid sealing membrane is sloped at an angle of at least 45 degreesrelative to the horizontal plane when the lid is not in use or notapplied to a container.
 45. A lid as defined in claim 36 wherein saidsidewall comprises a first sidewall and a second sidewall located apredetermined distance from said first sidewall, said sealing membranebeing sloped between said first and second sidewalls at said anglerelative to the horizontal when the lid is not in use.
 46. A lid asdefined in claim 36 wherein said elastic sealer is connected to saidsidewall, said sealing membrane being sloped and located below and apartfrom the bottom surface of said elastic sealer.
 47. A lid as defined inclaim 46 wherein said sealing membrane has a first end connected to saidelastic sealer and a second end movable relative to the bottom surfaceof said elastic sealer.
 48. A lid as defined in claim 47 wherein saidsecond end of said sealing membrane is positioned closer to the outeredge of said elastic sealer than said first end.
 49. A lid as defined inclaim 47 wherein said second end of said sealing membrane comprises asealing rim thicker than the part of said sealing membrane adjacent tosaid sealing rim.
 50. A lid as defined in claim 46 wherein said sealingmembrane approximately adapts one of L, C, sloped V, inverted T,inverted Y, U and sloped I shapes, at least part of said sealingmembrane designed to contact the interior surface of the container beingsufficiently thin and elastic to conform to the indents or protrusionson the interior surface.
 51. A lid as defined in claim 36 wherein saidside wall has at least one elastic pleat adapted to collapse when thelid is pressed, thereby expelling air out of said closed chamber, and tohave a memory to rebound to its original height when the lid is notpressed, thus generating vacuum in the closed chamber.
 52. A lid forsealing a container comprising: a top plate; a sidewall connected to thetop plate; a knob located on said top plate; wherein at least one ofsaid top plate and sidewall is adapted to seal to the container to forma closed chamber between said top plate and container; and wherein saidknob comprises a valve opening for communicating said closed chamberwith atmosphere and a valve sealer, said valve opening having a valvesidewall of a predetermined length adapted to form a frictional fit tosaid valve sealer to cause an airtight seal, said valve sealer beingadapted to move in said valve opening to cause at least a partial lossof said frictional fit to form an air passage between said closedchamber and atmosphere.
 53. A lid as defined in claim 52 wherein saidknob further comprises an extension to said valve sidewall, saidextension having a channel to cause said at least partial loss of saidfrictional fit to produce said air passage when said valve sealer movesinto said extension.
 54. A lid as defined in claim 52 wherein said knobis adapted to have a motion sealing distance for said valve sealerbetween about 0.5 mm and 15 mm to prevent leakage during storage due toaccidents or aging.
 55. A lid as defined in claim 52 wherein said knobfurther comprises a spring sufficiently strong to overcome the frictionforce of said frictional fit and cause said valve sealer to return intosaid valve opening after said valve sealer is moved to cause said atleast partial loss of said frictional fit to produce said air passage.56. A lid as defined in claim 55 wherein said spring comprises a platehaving a first end connected to the body of said knob and a second endconnected to said valve sealer, said plate being adapted to bendsufficiently to cause said valve sealer to move and lose said frictionalfit.
 57. A lid as defined in claim 55 wherein said spring comprises afirst spring for moving said valve sealer down and a second spring formoving said valve sealer up, said first and second springs being adaptedto keep said valve sealer in said valve opening during storage.
 58. Alid as defined in claim 57 wherein said second spring is stronger thansaid first spring to increase the sealing reliability of the lid duringstorage.
 59. A lid as defined in claim 55 wherein said knob furthercomprises a knob head connected to said valve sealer through a valveshaft and a knob body in which said valve sealer is hosted, said springbeing adapted to move said valve sealer up and down in said valveopening and having a first end immobilized to said knob head and asecond end immobilized to said knob body.
 60. A lid as defined in claim52 wherein said knob further comprises a second opening positionedupstream of said valve opening for receiving an evacuation deviceconnected to a vacuum pump to evacuate said closed chamber and a knobhead adapted to interact with the evacuation device to cause said atleast partial loss of said friction fit when the evacuation device isreceived in said second opening.
 61. A lid as defined in claim 52wherein said knob further comprises a knob head, a knob body having achamber above said valve opening, and a valve shaft connected to saidknob head and valve sealer,
 62. A lid as defined in claim 52 whereinsaid valve sealer is adapted to move among a first position in whichsaid valve sealer forms an airtight seal to said valve opening, a secondposition in which said valve sealer is at least partially above saidvalve opening to form a first air passage between said closed chamberand atmosphere, and a third position in which said valve sealer is atleast partially below said valve opening to form a second air passagebetween said closed chamber and atmosphere.
 63. A lid as defined inclaim 62 wherein said knob further comprises a knob head, wherein saidvalve sealer is adapted to form said second air passage when one pressessaid knob head, thus the lid, to remove the air from said closed chamberand to form said first air passage when one pulls said knob head toremove the lid from the container.
 64. A method of using a lidcomprising placing a lid on a container, pressing a knob of the lid downto form a first air passage to evacuate the container, thereby vacuumsealing the lid to the container, and pulling the knob up to form asecond air passage to release the vacuum, thereby lifting the lid offthe container.